实验3:数据库的简单查询和连接查询
一、 实验目的
熟练掌握和使用SQL Server查询分析器的使用方法,加深对SQL和Transact-SQL语言的查询语句的理解。熟练掌握简单表的数据查询和数据排序的操作方法。
二、 实验内容
1. 数据表的导入和导出操作
通过导入和导出功能实现数据表的转移和导入。 2. 简单查询操作。
该实验包括投影、选择条件表达、数据排序等。
三、 实验步骤
? 基本操作实验 I :通过导入和导出功能实现数据表的转移和导入。 步骤一:
建立数据库和表,并数据
步骤二:打开SQL Server管理平台,展开服务器和数据库,右击该数据库图标,从弹出的快捷菜单中选择“任务→导入数据”选项,启动数据导入向导工具,就会出现欢迎使用向导对话框,对话框中列出了导入向导能够完成的操作。
步骤三:单击“下一步”按钮,则出现选择数据源对话框,在该对话框中,可以选择数据源类型、文件名、用户名和密码等选项
。
步骤四:导出成功
? 基本操作实验 II:简单查询实验
1. To find all loan number for loans made at the Perryridge branch with loan
amounts greater than $1200.
select loan_number
from loan
where branch_name='Perryridge' and amount > 1200
2. Find the loan number of those loans with loan amounts between $900 and
$1,500
select loan number
from loan
where amount between 900 and 1500
3. Find the customer names and their loan numbers for all customers having a loan at
some branch.
select customer_name, T.loan_number, S.amount from borrower as T, loan as S where T.loan_number = S.loan_number
4. Find the number of tuples in the customer relation
select count (*)
from customer
5. Find the number of depositors in the bank
select count (distinct customer_name) from depositor
6. Find all customers who have both an account and a loan at the bank
select distinct customer_name from borrower
where customer_name in
(select customer_name from depositor )
7. Find the number of depositors for each branch. select loan_number
from loan
where amount is null
8. Find all loan number which appear in the loan relation with null values for amount
select loan_number from loan
where amount is null